Quantitative Nuclear Cardiography requires that non-invasive radioisotope methods produce results which are numerically comparable to those obtained at cardiac catheterization. This project develops the capacity of radionuclide methods to provide these measurements for all of the standard parameters of cardiac function (those obtained by catheterization) and in addition, suggests measurements which are readily available by radionuclide methods, but which are not usually sought. These include pulmonary blood volume, and dV/dt. In addition to developing these techniques, this study will validate their use by preparing them for acceptance by clinical cardiologists, and assessing their utility in decision making by these cardiologists.